In a supply chain of sign-making industry, moving a product from manufacturer to end customer involves rewinding and/or cutting of films or film-like material at different stages of the supply chain based on customer's needs. For example, poly-vinyl films may be rewound to one or more rolls of one or more desired lengths from a master roll, or one or more sheets may be cut out from the master roll. Further, a rewound roll or a master roll may be slit into two or more rolls of desired width. As such, the measuring, rewinding, cutting and slitting operations may be performed by user-operated rewinding machines.
During rewinding a roll from a master roll, a tension applied on the moving film or film-like material may be adjusted in order to provide a higher quality product. Further, tight tension control measures provide greater throughput. For example, if tension is not adjusted appropriately, wrinkles may form within the film resulting in wasted or defective product. Inadequate tension adjustment may also result in the outer layers of the roll crushing the inner layers and/or the inner layers may telescope out, either of which may render the roll unusable.
The inventors herein have recognized the above-mentioned issues. Accordingly, in one example, the issues described above may be addressed by a method for a winding device, comprising: transporting a rolled film-like media from a first roller mounted on a first lower shaft to a second roller mounted on a second upper shaft via a third middle shaft, the third middle shaft in a first position; and responsive to initiation of rewinding of the film-like media onto the second roller, adjusting the third shaft to a second different position. In this way, by retracting the middle shaft during the rewinding process, tension control may be improved.
As one example, during up-take of the film into a transportation head of the winding device, the middle shaft may be operated in a first position making contact with the material. By making contact with the film, the middle shaft facilitates feeding of the film through the transportation head, edge detection and initiation of measurement of the length of the film from the edge. However, during rewinding of the film, after the feeding, edge detection and initiation of measurement, the middle shaft may be retracted away from the film to a second retracted position. When operating in the second retracted position, the middle shaft is not in contact with the film, thus reducing the need for synchronization of the upper, middle, and lower shaft speeds during the rewinding operation. This provides greater control with tension adjustment as fewer parameters need to be adjusted while achieving proper uptake of the film into the transportation head and referencing of the film.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.
FIGS. 1, 2A, 2B, 3, 4, 8A and 9 are shown approximately to scale.